diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index a93ed81d..09bd47ac 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -986,8 +986,10 @@ Class.prototype = {
                 catch (e) {}
             }, this);
         }
+        return this;
     },
 
+    localizedProperties: {},
     magicalProperties: {}
 };
 Class.makeClosure = function makeClosure() {